Question

How would one do something like this in python

Mainstring:
     Sub1
     Sub2
     Sub3

then call upon each of those values by defining a Mainstring StringNumberOne
and

StringNumberOne.Sub1 = ""

Answer 1

First you define a class MainString. In the __init__ method (the constructor), you create the instance variables (Sub1, etc):

class MainString(object):
    def __init__(self):
        self.Sub1 = ""
        self.Sub2 = ""
        self.Sub3 = ""

Then you create an instance of the class. You can change the value of instance variables for that instance:

StringNumberOne = MainString()
StringNumberOne.Sub1 = "hello"